Both of which can lead to more harm than good. 

We don’t know any PMCs to recommend in the area mentioned, but since selecting the wrong PMC is usually more harmful than selecting a bad tenant, you might want to read our series about “How to Screen a PMC Better than a Tenant”:https://www.biggerpockets.com/member-blogs/3094/91877-how-to-screen-a-pmc-better-than-a-tenant-part-1-services-and-processesWe recommend you get management contracts from several PMCs and compare the services they cover and, more importantly, what they each DO NOT cover.

The tenants were menaced and physical harm was threatened to the point where I am considering installing a camera and security system.  

I've never been a huge fan of credit scores just because certain life events can really harm them despite a person being otherwise a great tenant.

I'm not looking for answers, I have a plan, but theres no harm in throwing the idea out here to the wolves and getting some feedback, so CHOW DOWN!

There is no harm in asking.

But he has to prove harm, which isn't his intent.....he just wants a settlement.

Any tenant who attempts to cause emotional harm to their landlord can be sued; even just writting about it on the internet is cause for legal damages!! 

I know there is a lot to be gained for doing the flipping yourself but DH and I struggle to find the time to put into them and I'm afraid the amount of time they'd spend vacant would do more harm than the improvement value.

I would like to say that putting properties under contract with no ability nor intention to close, then walking if not assigned, harms sellers.